Oscillating power tools generally have a motor, an output shaft, and a transmission that connects the motor to the output shaft and converts rotary motion of the motor to oscillating motion of the output shaft. The output shaft is coupled to an accessory attachment mechanism that is used to removably attach various types of accessories, such as cutting tools, saw blades, and sanding tools, to the output shaft. Different brands of oscillating power tools tend to have different, often proprietary, accessory attachment mechanisms. It is desirable to have oscillating accessories with a universal attachment portion that can be attached to a multitude of different brands of oscillating power tools.